These changes would allow you to ensure that useCache = false for the loadModules, loadDb, and saveCache calls.
Now, I have no idea how useCache = true could possible be set this early in the request flow as the only thing I can see that sets it is a successful call to
Mage_Core_Model_Config::loadModulesCache, which if you look at your stack trace is obviously returning false :/
My 100 router fix as discussed in this write the above is all based around the fact that generating the config with
useCache = true is a real killer. So, I'd pop this into your Magento instance to make absolutely sure that useCache = false for this bit of code.